The World Bank’s International Comparison Program (ICP) has just released its latest measures of price levels and GDP across 176 countries - and the results are striking. For the first time ever, the ICP finds that China’s total real (inflation-adjusted) income is slightly larger than that of the United States (US). In purchasing-power-parity (PPP) terms, China’s 2017 GDP was US$19.617 trillion, whereas the US’s stood at US$19.519 trillion.

Of course, when China’s total income is divided by its massive population, the picture changes. Although China’s per capita income has pulled ahead of Eg...